It is commonly desired to install “anchors” in a seabed or sea floor to provide mooring to one or more vessels or installations used in the offshore industry. Such anchors can be termed “pile anchors” or “anchor piles” or “mooring anchors” and the like. All of these anchors are intended to be capable of resisting both horizontal and vertical movement, and thus provide anchoring or stability to vessels, rigs, drilling or floating platforms, etc. in a manner known in the art.
Typically, such anchors are elongate hollow bodies which are driven into the seabed or sea floor, sometimes using “suction” within the anchor to increase the ability of the anchor (by means of negative pressure within it) to be pressed down into the seabed. Examples include U.S. Pat. No. 3,496,900, U.S. Pat. No. 5,915,326 and U.S. Pat. No. 7,527,455.
Such anchors as described above are generally relatively large to provide mooring or stability to drilling platforms. As such, they require one or more installation mechanisms such as hammers or drills or suction, to be installed. Typically, such anchors are 40-50 m long, and have a 5-10 m outer diameter.
‘Pin piles’ are very much smaller anchor piles. They are also well known in the art, generally being less than 10 m long or even 5 m long, with a diameter of a meter or less. Pin piles are clearly a magnitude smaller in size than the larger pile anchors, etc., making their provision and handling easier. Whilst they can also be used to anchor or moor some surface vessels or apparatus, they are more commonly used for assisting seabed or sea floor apparatus or operations. However, the installation of pin piles is currently still based on the use of the same large installation apparatus and methods as pile anchors, thus requiring the same (significant) CAPEX and OPEX as pile anchors.